Design Research On The Electro-Hydraulic Proportional Quantitative Casting Control System

Casting is the key process in foundry production. The yield and quality of castings are definitively influenced by the casting process. At present, the level of automation and productivity of casting equipment are not high in most of factories in our country. The level of automation and productivity of casting equipment are largely determined by the control system of its quantitative casting. Therefore, it is necessary to study the quantitative casting control system.Through comparing pouring method and quantitative method, after analyzing the questions of the active casting machines, the mechanical tilting pouring and weighing quantitative method were studied deeply. On this basis, The bilateral tilting rotary fixed-point casting is first presented, its pouring process and key factors are analyzed in detail. The structure of each part of the bilateral tilting rotary casting machine is designed, the digital prototype of casting machine is established using3D modeling software, and its structure and work principle are elaborated.In the design of the hydraulic system of the bilateral tilting rotary casting machine, electro-hydraulic proportional control valve is characteristic of simple principle, high control precision, strong anti-pollution ability, moderate price and so on. Therefore, the electro-hydraulic proportional directional valve is made the main control valve. The angular displacement control system is designed to control the casting ladle’s tilting angle. Angular displacement feedback, weight feedback and proportional valve are formed into a closed loop control system, so as to accurately control the casting quantity and improve the quantitative accuracy.Based on the digital prototype of the bilateral tilting rotary casting machine, the mathematical model of the control system is established. According to the mathematical model of the control system, its static characteristic is analyzed from two aspects:the stability and steady-state error, and the parameters of the system is calculated. On the first condition of the quantitative accuracy, the stability of the system is corrected by phase lag. On the basic of the analysis of the dynamic characteristics, the system was corrected by PID. The best combinations of PID parameters were determined by trial and error method. And digital simulation through Matlab software shows that bilateral tilting rotary casting system has a high quantitative control precision, good static and dynamic performance. The system can meet the expected design requirements.According to the structure of the digital prototype and key issue, the targeted experiment was carried out. The experiment result has proven that the bilateral tilting rotary fixed-point casting process is feasible, and the best casting parameters are found out. The results of the experiment provide a strong evidence for the application of the bilateral tilting rotary fixed-point casting.The topic selection aim at the actual production problems, and the key factors are researched deeply. The work of design research has a great theoretical significance, which has guiding value to the similar research, and a good popularization and application prospect.